Basic Measurements in Ophthalmology J Antony
INDEX
Page numbers followed by f refer to figure, and t refer to table
A
Abducent nerve 228
Adenoma, pituitary 169, 169f
Adie's pupil 91
Alkaptonuria 49
Allergy 228
Amacrine cells 129, 130
Amaurosis 225
Amenorrhea 171
Ampulla 201
Anisocoria, physiological 90
Annulus of Zinn 181, 224, 231
Anterior chamber 54f, 62, 64f
angle of 63
boundaries of 62, 62f
dimensions of 63f
measurements of 62, 63
Anterior ciliary vessels, foramina for 17
Anterior scleral foramen, external scleral margin of 16
Antiglaucoma surgeries 9, 56f
Applanation 71
Aqueous
circulation of 89
flare 68, 68f
humor 67, 69
channels 66f
composition of 68
functions of 69
measurements 68
nonprotein concentration of 69
outflow of 75
oxygen concentration of 69
Arachnoiditis, optochiasmatic 170
Arcus juvenilis 49f
Arcus senilis 48
Area of Martegiani 115
Area of sella 165
Areolar tissue
subcutaneous 180, 191
submuscular 174, 180
Argyll Robertson pupil 91
Artery, infraorbital 220
Ascorbate 69
Asteroid hyalosis 118
Axial proptosis 225
Axoplasmic transport 158
B
Basal lamina 28
inner 98
outer 98
Basement membrane 28
Baush and Lomb keratometer 38
Bayer's calculators 36
Berger's space 114, 115
Bicarbonate ions 69
Bipolar cells function 129
Bitot's spots 48, 49f
Blaskovics technique 190
Bleeding disorders 56
Blindness, ipsilateral 169f
Blood vessels 94
Blue limbal incision 57
Bone 211
forming lacrimal fossa 202f
frontal 211
maxillary 211
zygomatic 211
Bouquet of central cones 143
Bowman's layer 28
Bowman's membrane 28, 32, 46, 47
functions of 28
termination of 50, 51
Brain
inferior surface of 162f
sagittal section of 163f
Brow ptosis 174
Brow suspension 175
Bruch's membrane 97
structure of 97f
thickness of 98
Bulbar conjunctiva, attachments of 9
Buphthalmos 34, 35f
C
Cadaveric eye 21
Canal of Hannover 110
Canal of Schlemm 17, 47, 52, 55, 6466
Canaliculus, punctum of 200f
Canthal angle 187
Canthal tendon, lateral 182184, 218
Cantholysis, lateral 186, 195f
Capsular tension ring 118
Capsule of Tenon 9
Capsulotomy
anterior 104, 104f, 105
posterior 104, 105f
Carcinoma breast 214
Cardiovascular diseases 71
Carotid
artery, internal 162, 227
system
external 218
internal 218
Cataract
extraction
conventional extracapsular 57, 58f
intracapsular 57, 58f
hypermature 107
intumescent 100
surgery 9, 10, 31, 36, 56, 57f, 58f, 103, 104, 118
techniques of 57
Catarrhal ulcer 48
Cavernous sinus 228
Cells, horizontal 129
Central nervous system, part of 152
Cerebrospinal fluid 155, 162, 203
Chalazion 193f
surgery 193
Chemosis 225
Chiasma
anterior angle of 168
length of 161
part of 169f
posterior angle of 170
superior part of 170
Chiasmal lesions 168, 171
Chiasmatic cistern 162
Chloride ions 68, 69
Cholinesterase inhibitors 21
Choriocapillaris, outer basal lamina of 98
Choroid 96
dimensions of 96, 98
functions of 98
length of 96
structure of 96, 97f
thickness of 96
Choroidal detachment 55
Choroidal pigment 15
Ciliary arteries
long posterior 19
short posterior 19
Ciliary body 91, 95
anterior face of 62
capillaries of 69
dimensions of 94, 95
functions of 95
pars plana of 119
pars plicata of 119
parts of 92f
posteromedial surface of 81
structure of 92, 92f
surface marking of 95
total length of 95
Ciliary epithelial cells 94
Ciliary epithelium 93, 94
Ciliary flush 15
Ciliary muscle 92
contraction of 93
tone 67
Ciliary nerves
long 20
short 20
Ciliary process, structure of 94f
Ciliary sulcus 82, 84
average diameter of 82
Cloquet's canal 113115, 118
Closed angle glaucoma 70
Coaxial microincision cataract surgery 57, 58f
Collagen
diseases 15
fibers 118
vascular disorders, limbal manifestation of 48
Collarette, thickness of 89
Color-coded contour map 39
Computerized corneal topography 39
Cones, high density of 141
Congestion, circumcorneal 17
Conjunctiva 7, 9, 10, 10f, 32, 50, 190
bulbar 810
burns of 12
dimensions of 12
diseases of 46, 48
fornicial 8
lamina propria of 47
measurements of 6, 12
palpebral 186
portions of 7, 7f
squamous cell carcinoma of 49f
structure of 6, 6f
Conjunctival epithelium 11, 12f
Conjunctival flap 52
fornix-based 9, 9f, 54f
Conjunctival fornix 7, 182, 199f
Conjunctival impression cytology 11, 11f
Conjunctival sac 8
dimension of 8f
level of 12
Conjunctival scarring 12f
Conjunctivitis
phlyctenular 49f
vernal 49f
Connective tissues, condensation of 86
Contact lenses 31
Copper deposit 48
Cornea 2, 26, 32, 33, 35, 54, 62
abscess of 48
anterior
layer of 27
surface of 33f
Bowman's membrane of 47
central third of 36
curvature of 35, 41
dimensions of 26f
internal diameter of 17
layers of 27f, 32
measurements of 26, 44
posterior surface of 33f, 36
refractive index of 41
shape of 35
structure of 26, 27f
surface area of 32
thickness of 42f
topography of 39f
Corneal astigmatism
anterior 35
posterior 36
Corneal curvature
measurement of 37
normal variations of 35
Corneal decompensation 118
Corneal diameter 32, 34
enlarged 35f
horizontal 35f
measurement of 33
Corneal epithelium 27f
Corneal incision 56
Corneal injury 28
Corneal innervation 32
Corneal pachymetry 44
Corneal reflex, keratoscopic 38f
Corneal stroma 28f
subjacent fibers of 64
Corneal thickness 41, 42, 44, 72
measurement of 42
Corneal topographer 35
Corneal topographic zones 36, 37f
Corneal ulcers, marginal 48
Corneolimbal junction 50, 55, 79
Corneoscleral junction 17
Corneoscleral limbus 65
Corneoscleral meshwork 64
Corneoscleral tunnel incision, conventional square-shaped 60f
Corrugator supercilii 173
Cortex 102
anterior 105
peripheral 105
Cranial cavity 161
Cranial fossa 163, 163f
middle 163
Cranial nerves 152
Craniofacial anomalies 210
Craniofacial syndromes 187
Craniopharyngioma 168, 169
Cushing syndrome 171
Cyclocryotherapy 55
Cyclodestructive procedures 55, 95
Cysticercosis, intraocular 118
Cystoid
cicatrix 21
macular edema 144
D
Dacryocystectomy 185, 206
Dacryocystitis 203, 207f
acute 204f
chronic 204f
Dacryocystorhinostomy 185, 206, 208
Deep lamellar keratoplasty 29
Deep pretarsal aponeurosis 218
Demyelination 168
Depression 234
Descemet's membrane 29, 30f, 32, 46, 47, 55, 65
posterior surface of 30
termination of 29, 50, 51, 64
Diabetes mellitus 31, 71
Diabetic retinopathy, proliferative 118
Diaphragma sella 162
Dilator pupillae 86, 89
Diplopia 217, 222, 223
horizontal 223
Dorsum sellae 164
Down syndrome 210
Draeger tonometer 72
Drainage angle, measurements of 67
Dry eye 12
Dua's layer 29, 30f, 32
Duane's retraction syndrome 214
Dysgerminomas 169
Dyskeratosis, benign 48
Dysplasia, fibrous 227
Dystrophies 37
E
Ectasias 37
Ectopic pinealomas 169
Ectropion correction surgeries 194
Edinger-Westphal nucleus 86
Egger's line 115
Ehlers-Danlos syndrome 15
Electronic indentation tonometry 74
Emmetropes 16
Emphysema, surgical 221
Endocrine dysfunction 171
Endophthalmitis 118
postoperative 57
Endothelial cell
density 31
single layer of 85
Endothelium 30, 30f, 32
basal lamina of 29
specular micrograph of 31f
Enophthalmos 214, 215f, 222
measurements 215f
Entropion lower lid, correction of 194f
Entropion surgery 194
Enucleation 227
Epiretinal membrane surgery 118
Episclera 15
Episcleritis 49f
Epithelial cells 101
enlargement of 11
separation of 11
small 11
Epithelioma, intraepithelial 48
Epithelium 27, 32, 102
anterior 87
pigmented 94
basal lamina of 28
normal 11
posterior 87
primary function of 27
Erggellet's space 114
Ethmoid bone 211
Ethmoidal artery, anterior 223
Ethmoidal canals
anterior 216, 225
posterior 216, 225
Ethmoidal foramen, anterior 223
Everbush's technique 190
Exophthalmos 213
Extracellular space, small size of 101
Extraocular muscles
dimensions of 235, 235f
insertion of 16, 24, 236, 236f
measurements of 229
origins of 224
tone of 70
Eye 56, 99
anterior segment of 81
aqueous drainage system of 64
buphthalmic 35f
drainage system of 197
gross measurements of 1
pain of 221
swelling of 221
Eyeball 1
anterior segment of 99
center of 3
rotation of 3, 3f, 236, 238, 239f
diameter of 2
dimensions of 2f
equator of 2
general
dimensions 2
measurements of 4
structure of 1f
lower displacement of 222
nodal point of 3
outer coat of 14
parts of 85
posterior segment of 112
preserves shape of 24
structure 1
torsions of 238
Eyebrows 172, 172f, 173, 174
dimensions of 172
functions of 174
hairs, loss of 174, 175f
layers of 173, 173f
measurements of 172
structure of 173, 173f
Eyelids 1, 178
colobomas, reconstructions of 195
fibrous layer of 183, 183f
functions of 195
measurements of 178
F
Facial
expression, muscles of 180f
opening 209
Fasanella-Servat
operation 190
procedure, modification of 190
Fascia 202
bulbi 9
capsulopalpebral 184, 192
Fat, preaponeurotic pad of 181
Fetal nucleus 107
Fibers
arrangement of 167, 167f
bundles of 28f, 109
temporal 157, 167
Fibrous tissue layer, subcutaneous 173
Fissure
below ring transmit, part of 228
transmits, intermediate portion of 228
Fontalis muscle 176f
Foramen, zygomatic 218
Foramina
anterior group of 16
middle group 17
posterior 25
Fornices, extent of 8f
Fovea 128, 134, 135, 141, 151
centralis 134
depth of 143, 151
diameter of 143
dimensions of 143
externa 143
structure of 143f
thickness of 143
trochlearis 216
Foveal avascular zone 142f, 143
Foveal pit 143
Foveola 134, 141, 143, 151
Fracture 216, 224
blowout 223
floor 221f
lateral wall 186, 219
zygomatic 186
zygomaticomaxillary complex 219
Friedenwald nomogram 23f
Frontal bone, orbital plate of 215
Frontalis 173
muscle 176f
sling, steps of 176
Frontoethmoidal suture 215
Frontozygomatic suture 218
Full thickness lid tear, repair of 194f
G
Galactorrhea 171
Ganglion cell 141
layer 130, 132, 144, 145
thickness of 130
GDx printout 150f
Giant retinal tear 118
Gland, pituitary 161, 164, 165
Glands of Krause 197, 199
Glands of Wolfring 197, 199
Glandulae lacrimalis 198
Glaucoma 19, 23f, 31, 70, 80, 138f, 146
congenital 35f
disease
mild 71, 80
moderate 71, 80
severe 71, 80
early diagnosis of 75
evaluation of 42, 150
filtering bleb 48
genetic predisposition 70
infantile 21
pupillary block 83f
relief of 83
types of 70
Gliomas 168
Globe, support ligament of 218
Glucose 69
Goblet cell 6, 10, 10f, 11, 12f
density 10, 11
loss of 11, 12f
Goldmann tonometer 44, 72
Goldmann/Zeiss four mirror contact lens 146
Golgi apparatus 30
Gonioscopy 29
Gout, conjunctival episcleritis of 49
Granuloma 193f
removal of 193f
H
Haller's layer 97
Heidelberg retina tomograph 147
equipment 149f
printout 149f
Hemianopia 169f, 170
binasal 171
bitemporal 171
contralateral 168
inferior altitudinal 170f
Hemianopic reaction 91
Hemidesmosome formation 28
Hemorrhage 55, 224
subconjunctival 221
Henle's fiber layer 129, 143, 144
Horner's muscle 202
Horner's syndrome 214
Hruby lens 146
Hyaloid membrane
anterior 113
posterior 113, 118
Hyaloideocapsular ligament 115, 118
Hydrodilineation 106
Hydrodissection 105
Hydroprocedures 106, 106f
Hypermature shrunken lens 101f
Hypermaturity 101
Hypermetropia 16, 21
Hypertelorism 210
Hypertension, ocular 80
Hypoesthesia 219
infraorbital 222
Hypoglobus 222
Hypophysis cerebri 164
Hypotelorism 210
Hypothalamus, activity of 70
Hypothyroidism 174
Hypotony, ocular 80
I
Incision
chord length of 57, 58f
depth of 60
length of 61
size of 123
vertical 79
Inferior ophthalmic vein, tributaries of 229
Inferior orbital fissure
boundaries of 229f
dimensions of 229f
Inferior rectus muscle, dimensions of 232f
Infertility 171
Inflammations 168, 224, 228
Infraorbital nerve, injury of 222
Internal carotid artery, aneurysm of 228
Internal limiting membrane 131, 132, 144
Internal maxillary artery, sphenopalatine branch of 229
Intraocular foreign body, removal of 118
Intraocular lens 36
implantation 103
Intraocular pressure 21, 22, 22t, 33, 34, 65, 69, 70, 72, 73, 80
baseline 71, 80
measurement of 44, 70
normal 70
Intraocular tumors 118
Ipsilateral temporal retina 160
Iridectomy, peripheral 54f, 83f
Iridocylitis, acute 87f
Iris 85
anterior surface of 62
diameter of 87, 88f
dimensions of 89
epithelium 87f
functions of 88
layers of 85, 86f
muscles of 86f
posterior surface of 81
root of 89
structure of 85, 86f
thickness of 88, 88f
Iritis 91
Iron deposit 48
J
Jacod's triad 225
Juxtacanalicular trabecular meshwork tissue 55
K
Kasener compares 51
Kayser-Fleischer ring 48, 49f
Keratinzation 12
Keratitis 225
marginal 49f
phlyctenular 49f
Keratoconus 31, 40f
Keratocytes 29
Keratoglobus 34
Keratometer 35
Keratometric mires 38f
Keratometry 37
Keratoplasty 31
lamellar 29
penetrating 31
Keratoscope 35
Keratoscopy 38
Knee of Willebrand 168
Kuhnt Szymanowski procedure, modified 194
L
Lacrimal apparatus 1, 197
measurements of 197
Lacrimal bone 203, 211, 222
small portion of 204
Lacrimal canaliculi 197, 200
Lacrimal crest, anterior 223
Lacrimal fascia 202
Lacrimal fistula 204f
Lacrimal fossa 202, 207f, 223
dimensions of 203, 203f
Lacrimal gland 197, 198
accessory 197, 199
normal 199f
orbital portion of 198f
Lacrimal nerve 227
Lacrimal papilla 186
Lacrimal passages 197, 200, 205
dimensions of 200f, 201f
surface marking of 205f
Lacrimal puncta 197, 200
Lacrimal sac 198, 201, 202
disorders 203
surgeries 206f
measurements 206
Lactate 68, 69
Lamina cribrosa 19, 154
Lamina fusca 15, 96
Lamina papyracea 222
Large volume camp surgeries 56
Laser iridotomy 83f
LASIK 32
Lateral rectus, check ligament of 218
Lateral wall, bones of 218
Layer of Henle 143
Lens 81, 109, 118
anterior surface of 100
capsule 103, 103f, 110
colobomatous 100
congenital anomaly of 100
cortex 105
diameter of 99
dimensions of 99, 107
dioptric power of 101
epithelium 105
equatorial diameter of 93
fibers, regular arrangement of 101
functions of 102
intumescent 101f, 107
measurements of 99
normal 99f
diameter of 100f
thickness of 100
width of 100
posterior
curvature of 93
surface of 116f
power of 101
pump system of 101
radius of curvature of 100
refractive index of 101
sagittal thickness of 93
structure of 102, 102f
surgical anatomy of 102, 106f
suspensory ligament of 109
thickness of 100
weight of 101
zonule diaphragm 99
Lenticonus 101
Leprosy 174, 175f
Levator
action
assessment of 189f
measurement of 188
aponeurosis, lateral horn of 218
muscle, dimensions of 182f
muscular portion of 182
palpebrae superioris 188, 190
check ligament of 218
muscle 181, 195
portion of 7
resection 182, 190
Lid
ecchymosis of 221
edema 225, 228
emphysema of 223
free margin of 186
tear, full thickness 193
Ligament of Lockwood 218
Ligament of Weiger 83
Ligament of Whitnall 181, 188
Limbal border
anterior 50
posterior 50
Limbal incision 56, 57
Limbal line 50
Limbal stroma 79
Limbic keratitis, superior 48
Limbus 20, 46f, 56, 145
deep pigmentation of 49
dimensions of 49, 50f, 51, 51f
functions of 47
importance of 47
landmarks of 49, 50f, 52
limits of 46
measurements of 46
pannus, superior 48
structure of 47, 47f
surgical anatomy of 51, 51f
zones of 50, 51f, 52f
Lower conjunctival fornix, inferior suspensory ligament of 192
Lower lid
breadth of 185f
coloboma, reconstruction of 195f
gross measurements of 191, 191f
length of 185f
measurements of 191
movement 192
retraction 193
structure of 191, 192f
tarsal plate of 184, 192, 196
Lymphatics 223
Lymphoma 118
M
Macula 116, 135, 141, 151
portions of 142f
Macular area 134
Macular fibers 157, 158
Macular hole surgery 118
Macular pucker 118
Macular region 132
Macular star 144, 144f
Madarosis 174
Makay-Marg tonometer 72
Marcus Gunn pupil 91
Marfan's syndrome 114
Marginal reflex distance 189, 190f
Maxilla
frontal process of 222
orbital plate of 220
Maxillary antrum 204
Medial canthal tendon 183, 184
posterior limb of 182
Medial canthus
distance of 187f
rounding of 223
Medial palpebral ligament 185, 202, 203
Medial rectus 16, 122, 235, 236
muscle 230
Medial wall 222f
bones of 222
fracture 223
injury 223
Megalocornea 33
corneal diameter variation of 34f
simple 34
Megalophthalmos, megalocornea of 34
Meibomian glands 180
Melanocytes 86
Meningioma 168, 169, 227, 228
Meningitis 170
Microcornea 33
corneal diameter variation of 34f
Microincision cataract surgery 57, 58f
Microphakia 100
Microspherophakia 101, 101f
Middle cranial fossa
floor of 164
lateral borders of 164
Minimally invasive vitreous surgeries 123, 124f
Miosis 91
Mittendorf's dots 115
Moll's glands 180
Moraxella lacunata 48
Morgagnian cataract 100
Morphine 91
Mucin spots 11
Muller's cells 128130
Muller's fibers 144
Muller's muscle 7, 182, 183, 188, 195
dimensions of 182f
Mullerectomy 190
Muscle
extraocular 15, 119f
layer 173
plane 239f
superior oblique 232
Mydriasis 89, 91
Mydriatics 90
Myopia 21, 90, 115
N
Nanophthalmos 21
Nasal fibers 157, 158, 167
Nasal nerve, internal 223
Nasal quadrant 95
superior 41
Nasal retina 132
contralateral 160
Nasal retinal
fibers 160f
quadrant, inferior 167
Nasal vortex vein
inferior 17
superior 17
Nasociliary nerve 228
anterior ethmoidal branch of 223
Nasolacrimal canal 220, 225
Nasolacrimal duct 198, 203
obstruction, congenital 205
Nerve
fiber index 150
fiber layer 130, 132, 144, 153
abnormal 147f
normal 147f
frontal 227
infraorbital 220, 229
loop of Axenfeld 17
supratrochlear 216
zygomatic 229
zygomaticofacial 219
zygomaticotemporal 218
Neurilemma sheath 153
Neuroretinal rim 136
Nomogram 22
Noncontact tonometer 72
Non-keratinized stratified epithelium 6
Nonprotein nitrogen 69
Normal retina, color of 133
Nuclear layer
inner 129, 131, 144
outer 129, 131, 143
Nucleus 102, 106
embryonic 107
O
Oblique muscle, inferior 220, 234
Ochronosis 49
Oculomotor nerve
inferior division of 228
irritation of 91
paralysis 90
superior division of 228
Oncotic pressure 118
Open angle glaucoma 70
primary 65
Open sky vitrectomy 120, 120f
Ophthalmic artery
aneurysm of 227
recurrent branch of 228
Ophthalmic vein
inferior 228
superior 228
Ophthalmoplegia 228
Ophthalmoscope 133
Ophthalmoscopy 146
Optic atrophy
consecutive 138, 139f
postneuritic 139, 140f
primary 138, 139f
Optic axis 3f, 4, 4f, 236, 237f
Optic canal 223, 225, 226f
diameter of 226
enlargement of 227
Optic chiasma 155, 160f-163f, 164, 165, 167, 167f, 168
central part of 169
dimensions of 161, 161f
measurements of 160
portions of 161f
position of 161
Optic disk 116, 134, 135, 137f, 138, 151, 154f
color variations of 138
drusen 140f
measurements of 135
melanocytoma of 141f
near 98
Optic foraminae 164
Optic nerve 20f, 152154, 155f, 213
chiasmal junction 168, 169f
contralateral 167
dimensions of 153f
diseases of 90, 91
distal portion of 156f
fiber 156, 159, 160, 167
extent of 152f
layer 147
functions of 158
gliomas 227
head 70, 147
intracanalicular portion of 155
intracranial portion of 160
intraocular portion of 154f
measurements of 152, 159
portions of 153f
proximal portion of 156, 157, 157f
retrolaminar layer of 154
sheath meningioma 227
Optic neuritis 225
Optic neuropathy, anterior ischemic 140f
Optic papilla 153
Optical canal 156f
dimensions of 226f
Optical coherence tomography 43, 138, 147
Optical pachymetry 42
Optical system, different parts of 24
Ora serrata 19f, 119f, 135, 145, 151
approximate distance of 5f, 20f
distance of 145
near 98
Orbicularis oculi 173, 180, 202
muscle 180f
orbital portion of 192
Orbit 1, 209, 209f
base of 209
blowout fracture of 214
bones of 211f
communications of 225
configuration of 213, 213f
depth of 209
dimensions of 209, 210f
emphysema of 223
eyeball relationship 213
floor of 219, 220f
lateral wall of 186, 217, 221f
measurements of 209
medial wall of 222
roof of 215, 216f
thinnest part of 222
walls of 211, 212f, 215
Orbital apex 223, 224f
syndrome 224, 225
Orbital axis 236, 237, 238f
Orbital cavity 213
Orbital cellulitis 214
Orbital conjunctiva 7
Orbital fissure
inferior 225, 228, 229f
superior 224, 225, 227, 227f, 228
Orbital floor
bones of 220
fracture 221
injury 221f
Orbital hemorrhage 221
Orbital index 210
Orbital lobe 197, 198
Orbital margins 211
bones of 212f
inferior 212
lateral 211
Orbital periostitis 224
Orbital plane 236
Orbital plate 222
Orbital roof 216
bones of 215
fracture 217
Orbital septum 7, 181, 183, 184, 202
Orbital tissues, fibrous contraction of 214
Orbital tubercle, lateral 218
Orbital wall
destruction of 214
injury
lateral 217f, 219f
medial 223f
posterior extremities of 223
Orbscan 40, 43
Organs, edge of 48
P
Pachymeter 42, 43f
Paget's disease 227
Pain, neuralgic 225
Palatine bone 211
orbital process of 220
Pallid disk edema 139, 140f
Palpebral fissure 186
dimensions of 186f
width of 189
Palpebral ligament 183, 184, 186
Palpebral lobe 197, 198
Palpebral muscle, inferior 184
Pansinusitis 228
Papery white disk 139f
Papilledema 139f
Parafovea 134, 141, 143, 151
Paralysis, pupillary 91
Paranasal air sinuses 221
Pars orbicularis 110
Pars plana 91, 95, 96, 110, 119f
incision 55, 56
surgeries 55, 56f
surgical procedures 95
vitrectomy 120, 121, 121f, 122f, 124f
incisions 122
Pars plicata 94, 96
distance of 119f
vitrectomy 120, 124
Patellar fossa 115
edge of 111
Pellucid marginal degeneration 48
Pemphigus 12
Pentacam 40f, 43
Pericapsular membrane 102
Perifovea 134, 141, 143, 151
Periorbital tissues, communications of 221
Periostitis 228
Perkin's tonometer 72
Petit's canal 114
Phacoemulsification 57, 58f
Phlyctenular disease 48
Pigment cells 86
Pilocarpine 65
Pinguecula 48
Pit, floor of 143
Plasma 69
Plexiform layer
inner 130, 132, 144
outer 129, 131, 143
Pneumatic tonometer 72
Posterior chamber 81
boundaries of 81f
dimensions of 84
measurements of 81
parts of 81, 82f
volume of 84
Posterior ciliary arteries, foramina for 19
Pre-Descemet's dystrophies 29
Procerus muscle 174
Proptosis 213, 214f, 217, 221, 228
measurement 214f
Protein 69
Provocative test 21
Pseudoexfoliation syndrome 103
Pterygium 48, 49f
Pterygopalatine ganglion, orbital branch of 229
Ptosis 217, 225, 228
correction of 175f, 176, 190
measurements of 189
mild congenital 191
moderate 190f, 191
severe 190f
surgery 175
Pupil 89
size 89, 90f
enlargement of 89
Pupillary diameter 90
Pupillary reactions 90
Pupillary zone width 89
Q
Quadrantanopia, superior 168
R
Raised intracranial tension 227
Recesses of Khunt 82
Recti muscle 119
insertions 232
Recti, vertical 239f
Rectus
inferior 16, 122, 235, 236
lateral 16, 122, 235, 236
muscle
inferior 231
lateral 230, 230f
superior 7, 230
Red swollen disk 139f
Refractive index 41, 107, 118
Refractive power 41
Refractive surgeries 42
Reticulum cell sarcoma 118
Retina 126, 134f
anterior 133, 134, 151
blood vessels of 116
central 133, 134
diameter of 151
diseases of 90
extent of 132, 132f, 146f
general
features of 132
structure of 127
histological structure of 127f
histopathology of 147
layer-by-layer structure of 126f
measurements of 126, 151
normal 133f, 148f
peripheral 133135, 145, 151
posterior 133, 134, 151
shape of 132
surface
area of 151
marking of 146f
thickness of 126f, 132, 133f, 151
topography of 133
width of 151
Retinal detachment
primary 118
surgeries 9
Retinal layers, measurement of 131
Retinal nerve fiber layer 146, 150
damage of 75
Retinal pigment epithelium 126, 127, 131, 142
functions of 127
Retinal quadrant, superonasal 168
Retinal vein occlusion 118
Retinal vessels, central 155f
Retinopathy of prematurity 118
Rheumatoid arthritis 49f
Ring ulcer 48
Road traffic accidents 217
S
Sac
lowermost portion of 202
massage 205, 206f
tumors of 203
upper portion of 202
Sattler's layer 97
Scanning laser
ophthalmoscopy 75
polarimetry 147, 149
Scar tissue 28
Schiotz tonometry, calibration of 22, 73f
Schlemm's canal 52, 54, 64, 65
Schwalbe's line 29, 47, 50, 51
Schwann cell sheath 32
Sclera 8, 9, 14, 15, 20
dimensions of 14f
diseases of 48
dorsal surface of 20f
functions of 24
measurements of 14, 24
peripheral 49
radius of curvature of 2
small anterior portion of 62
structure of 15
surface of 19f
temporal 16
thickness of 15
weak areas of 20, 21f
Scleral apertures 16
Scleral canal 136
Scleral coat, coronal diameter of 14
Scleral dimensions 14
Scleral flap
lamellar 54f
thickness of 54f
Scleral foramen, posterior 19
Scleral foramina 16f, 25
Scleral incision 56, 58
Scleral indentation 9
Scleral margin, internal 17
Scleral pocket incision 58
Scleral rigidity 20
calculation of 23f
Scleral spur 52, 65
Scleral stroma 15
Scleral surface, posterior 153
Scleral tunnel 58
corneal valve incision 60f
incision 80
architecture of 59
classical 58
conventional 59
limits of 60
Scleritis 21
Sclerolimbal junction 50, 52
Sclerotic carotid arteries 170
Sclerotomy, posterior 56
Scotoma, central bitemporal hemianopic 168
Sella
depth of 165
diameter of 165
dimensions of 165f
measurements of 165
portions of 164f
turcica 162, 164, 165
volume of 165
Shwalbe ring 64
Sickle cell retinopathy 118
Silvery striated appearance 146
Skin 173, 179, 191, 202
of eyelids, tuberculosis of 174
Small incision cataract surgery 57, 58f, 61f
Sodium ions 69
Specular microscope 30f
Sphenoid
body of 222
bone 211
primary tumor of 228
greater wing of 218
lesser wing of 216
wing meningioma 224
Sphenoidal air sinus 162
Sphincter pupillae 86, 89
Squamous cell carcinoma 48, 49f
Squint
concomitant 239
horizontal 239
paralytic 240
surgical correction of 239
vertical 241
Stab incision 123, 123f
Staphylococcal toxin 48, 49f
Steatoblepharon 193
Stereophotography 147
Steven Johnson syndrome 12
Strabismus surgery 15
Stroma 28, 32, 86, 93, 97
functions of 29
Substantia propria 28
Sulcus chiasmaticus 164
Superficial scleral flap 52
Superior oblique muscle, dimensions of 233f
Superior ophthalmic vein, occlusion of 228
Superior orbital fissure, medial end of 223
Superior quadrantanopia, contralateral 169f
Superior rectus muscle
dimensions of 231f
sheath, expansion of 218
Suprachoroidal lamina 96
Suture
double-armed 175f
zygomaticofrontal 215, 216
zygomaticosphenoid 218
Sympathetic system, palsy of 91
Synechia, posterior 87f
Systemic disorders 70
T
Tarsal conjunctiva 7, 192
Tarsal muscle, inferior 192
Tarsal plate 176f, 183
dimensions of 185f
surgical importance of 193
Tears, functions of 199
Telecanthus 187
Temporal vortex vein, inferior 17
Tenon's capsule 9, 10, 15, 47, 50
Tenon's fascia 9, 52
Tension glaucoma
low 80
normal 80
Terrien's marginal degeneration 48
Tonic pupil of Adie 91
Tonography 75
technique of 76
Tonometers 71, 72
Tonometry 70, 71
Tonopen 72
Topography 37
Tournay's reaction 90
Trabecular meshwork 52, 64
Trabecular tissue block 54f
Trabeculectomy 52
ostium 54f
steps 54f
Trabeculotomy 54
Trachoma 12
Trachomatous pannus 49f
Transscleral laser cyclophotocoagulation 55, 95
Traquair junctional scotoma 168, 169f
Trauma 169, 187, 228
Traumatic telecanthus 223
Trochlear
fossa 216
injury 223
nerve 228
Tuber cinereum 162
Tuberculum musculare 216
Tuberculum sellae 164
Tumors 168, 170, 224
Tunnel incision 123
internal corneal lip of 60
Turbinate bone, inferior 204
U
Ultrasonic pachymetry 43
Upper eyelid, structure of 181f
Upper lid
breadth of 178f
elevation 188
excursion 188
gross measurements of 178
length of 178f
margin 189
structure of 178, 179f
tarsal plate of 184f, 196
Urea 69
Uveal meshwork 64
Uveal tract 85
general dimensions of 85f
measurements of 85
parts of 85f
Uveitis 115
anterior 17
Uveoscleral outflow 67, 92
Uveoscleral pathway 67
V
Vasculitis 118
Vein, infraorbital 220
Vernal disease 48
Videokeratography 39
Viscocanalostomy 54
Viscosity 118
Vision
considerable loss of 225
contralateral hemified of 160
Visual acuity 142
Visual axis 3, 4f, 236, 236f-238f
opacification 104
Visual field defects 168
Visual impulses, conduction of 158
Visual loss 217
Vitrectomy 55, 118, 119f
measurements 118
surgeries, microincisional 123
types of 120
Vitreous 112, 114f, 117f
anterior surface of 81
base 116, 118
posterior 116
region 132
core 113
cortex 113, 118
dimensions of 118
face, anterior 114
functions of 117
hemorrhage, nonresolving 118
humor
measurements of 112
transparency of 117
incarceration 118
membranes 118
opacities 118
parameters 117
primary 113
prolapse 118
secondary 113
structure of 112, 112f
surface, posterior 115
surgical removal of 118
tertiary 113
topography 114
Vortex veins 17
approximate distance of 18f
positions of 18
W
Waardenburg syndrome 187
Walkers field loss 169
Weigers ligament 111
Wheelers operation, modified 194
White limbal incision 57
Whitnall's ligament 218
Whitnall's tubercle 218
Wieger's ligament 114
X
X-ray skull 221f
Y
Yellow swollen disk 139
Z
Zonular bundles 110, 110f
anterior 110, 111
posterior 110, 111
Zonular fibers, posterior group of 95, 96
Zonular fibrils, length of 110
Zonular fork 110
Zonular lamella 102
Zonular plexus 110
Zonules 81, 109, 109f, 115
dimensions of 109
extent of 109, 111
functions of 111
hyaloid 111
insertion of 109
loosening of 93
measurements of 109
of Zinn, measurements of 109
parts of 110
posterior limbs of 110
resistance of 110
Zygoma 218
Zygomatic bone, orbital surface of 218, 220
×
Chapter Notes

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General Configuration and Gross Measurements of EyeCHAPTER 1

Eye consists mainly of Eyeball, Ocular adnexa (eyelids, lacrimal apparatus and orbit), their vascular connections and neurological pathways.
 
EYEBALL
 
Structure (Fig. 1)
Structurally the eyeball has three walls performing different visually vital functions, enclosing various intraocular structures like lens, vitreous cavity enclosing the vitreous and the anterior and posterior chambers filled with aqueous, arranged in order so that light comes to a focus on the retina resulting in image formation. The walls of the eye are as follows:
zoom view
Fig. 1: General structure of eyeball.
2
  • Outer wall: Is mainly protective in function and is made of cornea in front and sclera behind.
  • Middle wall: Gives nutrition to many parts of eye and has three portions— iris, ciliary body and choroid.
  • Inner wall: Performs predominantly neurological function—the retina.
 
General Dimensions
Eye ball is not a perfectly spherical globe, as its anterior and posterior segments have different curvatures.
Anterior 1/6th of outer wall, the cornea is more curved (steeper) than posterior 5/6th, the sclera which is less curved (flatter) with a transitional zone in between them (limbus)(Fig. 2).
 
Radius of Curvature of Globe
  • Radius of curvature of the anterior portion (cornea) is about 7.8 mm.
  • Radius of curvature of the posterior portion (sclera) is about 12 mm.
    Summit of the curved anterior portion is the anterior pole and the apex of curved posterior portion is the posterior pole of the globe.
 
Diameter of Eyeball
Anteroposterior diameter (length) of eye ball is about 24 mm. Vertical diameter is 23.5 mm.
 
Equator of the Eyeball
  • External (Geometric) equator: Externally the equator of the eye ball is a circular line drawn on the exterior surface of the ball equidistant from anterior and posterior pole. The circumference of equator is about 71 to 75 mm.
  • Anatomical equator: Since the eye is slightly anatomically tilted backwards on temporal side for 1 to 1.5 mm and slightly nasally and sclera buldges slightly temporally, circle representing the anatomical equator may not be exactly in the middle of the globe.
    zoom view
    Fig. 2: Dimensions of eyeball.
    3
  • Surgical equator: Is the widest diameter of the globe in coronal plane.
  • Clinical equator: Is an imaginary line drawn along the ampullae of vortex vein as seen on fundus examination (Fig. 3).
Center of (geometrical) eyeball: Center of eye ball is about 12 mm behind the anterior pole of globe.
Center of rotation of eyeball: Center of rotation of eyeball is slightly behind the center of the eyeball and is about 13 mm behind the anterior pole.
Nodal point of the eyeball: Different points of visual field are connected to the retinal points by visual planes, each of them passing through the nodal point of eye. This point is situated in the posterior pole of the lens and is about 7.2 mm behind the apex of cornea (Fig. 4).
 
Visual Axis
Visual axis is an imaginary line connecting object of fixation, nodal point of the eye and fovea.
zoom view
Fig. 3: Internal (clinical) equator.
zoom view
Fig. 4: Optic axis, nodal point and center of rotation of eyeball.
4
zoom view
Fig. 5: Optic axis, visual axis and angle gamma.
zoom view
Fig. 6: Optic axis, visual axis, pupillary line and angle kappa.
 
Optic Axis
Optic axis passes from a point 0.25 mm nasal to the center of cornea, lens, center of rotation of eyeball and approximately through the center of pupil intersecting visual axis at nodal point and extent more nasally posteriorly. Pupillary line passes through center of cornea and center of pupil almost near the optic axis.
The angle between visual axis and optic axis is called angle gamma. This angle is assessed clinically at the pupillary plane (not very accurate) and is called angle Kappa also (Figs. 5 and 6).
 
SUMMARY OF GENERAL MEASUREMENTS OF EYEBALL (FIG. 7)
  • Radius of curvature anterior 1/6th of eyeball (cornea)
:
8 mm
  • Radius of curvature of posterior 5/6th of eyeball (sclera)
:
12 mm5
  • Length (anteroposterior diameter) of eyeball
:
24 mm
  • Vertical diameter of eyeball
:
23 mm
  • Horizontal diameter of eyeball
:
23.5 mm
  • Center of eyeball (geometrical)
:
12 mm behind apex of cornea
  • Nodal point of eyeball
:
7.2 mm behind apex of cornea
  • Center of rotation of eyeball
:
13 mm behind anterior pole
  • Distance of limbus to ora serrata
:
8 mm
  • Distance of ora serrata to equator
:
6 mm
  • Distance of limbus to equator
:
14 mm
  • Weight of eyeball
:
7.15 grams in adult and 3 grams in infant
  • Surface area
:
22.86 cm2
  • Specific gravity
:
1.077
  • Volume
:
7.2 mL
zoom view
Fig. 7: Approximate distance of ora serrata, equator and vortex veins in mm from limbus as marked on surface of sclera.